Flexural Theory Of Reinforced Concrete Hollow-slab Bridge Strengthed By CFRP Material And Its Application

China is in the period of rapid development of transportation construction. At the same time, because of overload, lack of maintenance and so on, there is an emergent need for numbers of bridges to be reinforced and strengthened. Carbon Fiber Reinforced Plastic (CFRP) is extensively used in reinforcement of bridges for its high strength and efficiency, light weight and good durability, convenience in construction, no influence on traffic and hardly changing the shape under bridge. At the present time, most of the research for CFRP is on strengthened models in laboratory, research on hollow slabs which are applied to bridges is correspondingly less.The thesis is based on a simply supported hollow-slab type RC bridge in Chengdu-Chongqing highway. First, the CFRP reinforcement theory and its research achievement are summarized. Finite element method and loading test are combined to make contrastive analysis of strengthen effect for the RC hollow-slab type bridge. Some wokes have finished in the following aspects:(1) Calculation of flexural capability of the deteriorated bridge by hinge-jointed plate method indicted that bridge's flexural capability reserve was not adequate. Based on the summary of calculation theories of flexural capability of reinforced concrete beam strengthed by CFRP, strengthening design for the bridge was made according to limit state method. The design method applied to the same type of bridges, which were strengthened by CFRP.(2) Three-dimensional model was made for the test bridge before and after strengthening by finite element method. The thesis compared and analyzed the change situation of girders's bending and stain on the bottom of bridge under the most unfavorable conditions. Results of analyse indicted that strengthening by CFRP could improve bridge's flexural capability effectively and increased its bending stiffness in certain degree.(3) The loading test project was designed for the test bridge before and after strengthed by CFRP. The test detected bending values of bridge's control sections under the test loading conditions, stain on the bottom of bridge was detected too. Comparation and analysis were made between field measured values and that calculated by finite element method before and after strengthened. Analysie of bridge's strengthening effect offered reference to the CFRP strengthening effect evaluation in the same type of bridges.(4) Summary of CFRP strengthening construction technology was made, and strengthening methods of CFRP were preliminary discussed.